Ben 10, Season 2

Ben 10 (retroactively known as Ben 10 Classic) is an American animated series that aired on Cartoon Network. The series is about a 10-year-old boy named Ben Tennyson who gets a watch-style alien device called the "Omnitrix". Attached to his wrist, it allows him to transform into 10 different alien creatures with different abilities, allowing him to fight evil from Earth and space with his cousin Gwen and grandfather Max.